Why should the secondary side of a current transformer be strictly prevented from open circuit during operation?During normal operation of a current transformer, the magnetomotive force generated by the secondary current demagnetizes the magnetomotive force produced by the primary current, resulting in a very small excitation current and a small total magnetic flux in the iron core.Switch loop resistance testerfeatures accurate measurement and stable performance, suitable for on-site high-voltage switch maintenance in power and power supply departments, as well as for loop resistance testing requirements of high-voltage switch factories. The induced electromotive force of the secondary winding does not exceed several tens of volts. If the secondary side is open-circuited, the demagnetizing effect of the secondary current disappears, and the primary current completely becomes the excitation current, causing a sharp increase in the magnetic flux in the iron core, which becomes highly saturated. Moreover, due to the large number of turns in the secondary winding, according to the law of electromagnetic induction E=4.44fNB, a very high voltage (even up to several thousand volts) will be generated across the secondary winding, which may not only damage the insulation of the secondary winding but also seriously endanger personal safety. Furthermore, the sharp increase in magnetic flux density increases core losses, causing severe heating and even burning of the insulation. Therefore, an open circuit on the secondary side of a current transformer is absolutely not allowed, and it is a major taboo for electrical test personnel. For the above reasons, el

 ectric fuses must not be installed in the secondary circuit of a current transformer; the secondary circuit is generally not switched, and if switching is necessary, reliable measures should be taken to prevent open circuits.